1. Field of the Invention
The present invention relates to a display device, a display method, and a computer product.
2. Description of the Related Art
Conventionally, two tasks are present regarding heat generation from lighting of an optical source, in a battery-powered compact display device. A first task is reduction in energy loss due to heat generation following lighting of an optical source, and an improvement in efficient utilization of energy by effective use of thermal energy. A second task is realization of an efficient cooling system requiring a reduced space. In order to achieve these tasks, it is known that a display device includes a thermoelectric conversion element having a heat to electricity conversion effect and an electricity to heat conversion effect, a temperature detector that measures and detects a temperature of an optical source or periphery of the optical source, and a thermoelectric conversion element function switch controller that switches a function of the thermoelectric conversion element to either a heat to electricity conversion generation function or an electricity to heat conversion electron cooling function, based on temperature information from the temperature detector. It is disclosed in, for example, Japanese Patent Application Laid-Open (JP-A) No. 2004-361553.
A new type of light emitter that can autonomously emit light is also provided. This light emitter has flexibility, and has a sheet shape. The light emitter includes a layer piezoelectric element that generates electricity, a layer organic electro luminescence (EL) element that is laminated on the piezoelectric element via an insulation layer and emits light, a first protection layer, and a second protection layer. The light emitter also has a waterproof unit that protects the piezoelectric element and the organic EL element from water or moisture, and an electronic circuit that electrically connects between the piezoelectric element and the organic EL element. This light emitter is supported by an adherend. When the piezoelectric element is deformed by the adherend moving or when the piezoelectric element is got vibrations, the piezoelectric element generates electricity. The organic EL element emits light based on electricity generated by the piezoelectric element, as disclosed in, for example, JP-A No. 2002-63801.
An organic EL light emission display device with low power consumption is also provided. This kind of organic EL light emission display device has plural transparent organic EL light emission elements disposed in a pattern on one of the surfaces of a transparent substrate, each transparent organic EL light emission element including a transparent electrode layer, a transparent organic light emitting material layer, and a transparent cathode electrode layer. Solar cells are disposed on the other surface of the transparent substrate. The solar cells and the organic EL light emission elements are electrically connected to each other, as disclosed in, for example, JP-A No. 2002-6769.
According to the conventional technique described in JP-A No. 2004-361553 or No. 2002-6769, a power generation circuit having a power generation function is separately provided on a display panel, for the display device to generate electricity. Therefore, there is a problem that the display device has a larger size than is necessary, which leads to poor portability of the device.
According to the conventional technique described in JP-A No. 2002-63801, the display device incorporates other parts such as the piezoelectric element. Therefore, the number of parts and cost thereof increase. When the display device does not include a power generation function, only a charged cell supplies power to the display device, which limits an operating time of the display device.